<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <title>JSDoc: Source: utils/positionUtil.js</title>

    <script src="scripts/prettify/prettify.js"> </script>
    <script src="scripts/prettify/lang-css.js"> </script>
    <!--[if lt IE 9]>
      <script src="//html5shiv.googlecode.com/svn/trunk/html5.js"></script>
    <![endif]-->
    <link type="text/css" rel="stylesheet" href="styles/prettify-tomorrow.css">
    <link type="text/css" rel="stylesheet" href="styles/jsdoc-default.css">
</head>

<body>

<div id="main">

    <h1 class="page-title">Source: utils/positionUtil.js</h1>

    



    
    <section>
        <article>
            <pre class="prettyprint source linenums"><code>/**
 * 各地图API坐标系统比较与转换;
 * WGS84坐标系：即地球坐标系，国际上通用的坐标系。设备一般包含GPS芯片或者北斗芯片获取的经纬度为WGS84地理坐标系,
 * 谷歌地图采用的是WGS84地理坐标系（中国范围除外）;
 * GCJ02坐标系：即火星坐标系，是由中国国家测绘局制订的地理信息系统的坐标系统。由WGS84坐标系经加密后的坐标系。
 * 谷歌中国地图和搜搜中国地图采用的是GCJ02地理坐标系; BD09坐标系：即百度坐标系，GCJ02坐标系经加密后的坐标系;
 * 搜狗坐标系、图吧坐标系等，估计也是在GCJ02基础上加密而成的。
 */

const pi = 3.1415926535897932384626
const a = 6378245.0
const ee = 0.00669342162296594323

function outOfChina(lat, lon) {
  if (lon &lt; 72.004 || lon > 137.8347) {
    return true
  }
  
  return lat &lt; 0.8293 || lat > 55.8271;
  
}


function transformLat(x, y) {
  let ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x));
  ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;
  ret += (20.0 * Math.sin(y * pi) + 40.0 * Math.sin(y / 3.0 * pi)) * 2.0 / 3.0;
  ret += (160.0 * Math.sin(y / 12.0 * pi) + 320 * Math.sin(y * pi / 30.0)) * 2.0 / 3.0;
  return ret;
}

function transformLon(x, y) {
  let ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x));
  ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;
  ret += (20.0 * Math.sin(x * pi) + 40.0 * Math.sin(x / 3.0 * pi)) * 2.0 / 3.0;
  ret += (150.0 * Math.sin(x / 12.0 * pi) + 300.0 * Math.sin(x / 30.0 * pi)) * 2.0 / 3.0;
  return ret;
}


function transform(lat, lon) {
  if (outOfChina(lat, lon)) {
    return {lat, lon}
  }
  let dLat = transformLat(lon - 105.0, lat - 35.0);
  let dLon = transformLon(lon - 105.0, lat - 35.0);
  let radLat = lat / 180.0 * pi;
  let magic = Math.sin(radLat);
  magic = 1 - ee * magic * magic;
  let sqrtMagic = Math.sqrt(magic);
  dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);
  dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi);
  let mgLat = lat + dLat;
  let mgLon = lon + dLon;
  return {lat: mgLat, lon: mgLon}
}

/**
 * 84 to 火星坐标系 (GCJ-02)
 * @param lat
 * @param lon
 * @return {null|{lon: *, lat: *}}
 */
export function gps84ToGcj02(lat, lon) {
  if (outOfChina(lat, lon)) {
    return null;
  }
  
  let dLat = transformLat(lon - 105.0, lat - 35.0);
  let dLon = transformLon(lon - 105.0, lat - 35.0);
  let radLat = lat / 180.0 * pi;
  let magic = Math.sin(radLat);
  magic = 1 - ee * magic * magic;
  
  let sqrtMagic = Math.sqrt(magic);
  dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);
  dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi);
  let mgLat = lat + dLat;
  let mgLon = lon + dLon;
  return {lat: mgLat, lon: mgLon}
}

/**
 * 火星坐标系 (GCJ-02) to 84
 * @param lat
 * @param lon
 * @return {{lon: number, lat: number}}
 */
export function gcjToGps84(lat, lon) {
  const gps = transform(lat, lon);
  const lontitude = lon * 2 - gps.lon;
  const latitude = lat * 2 - gps.lat;
  return {lat: latitude, lon: lontitude}
}

/**
 * 火星坐标系 (GCJ-02) 与百度坐标系 (BD-09) 的转换算法 将 GCJ-02 坐标转换成 BD-09 坐标
 * @param ggLat
 * @param ggLon
 * @return {{lon: number, lat: number}}
 */
export function gcj02ToBd09(ggLat, ggLon) {
  let x = ggLon, y = ggLat;
  let z = Math.sqrt(x * x + y * y) + 0.00002 * Math.sin(y * pi);
  let theta = Math.atan2(y, x) + 0.000003 * Math.cos(x * pi);
  let bdLon = z * Math.cos(theta) + 0.0065;
  let bdLat = z * Math.sin(theta) + 0.006;
  return {lat: bdLat, lon: bdLon}
}

/**
 * 火星坐标系 (GCJ-02) 与百度坐标系 (BD-09) 的转换算法 * * 将 BD-09 坐标转换成GCJ-02 坐标
 * @param bdlat
 * @param bdlon
 * @return {{lon: number, lat: number}}
 */
export function bd09ToGcj02(bdlat, bdlon) {
  let x = bdlon - 0.0065, y = bdlat - 0.006;
  let z = Math.sqrt(x * x + y * y) - 0.00002 * Math.sin(y * pi);
  let theta = Math.atan2(y, x) - 0.000003 * Math.cos(x * pi);
  let gglon = z * Math.cos(theta);
  let gglat = z * Math.sin(theta);
  return {lat: gglat, lon: gglon}
}

/**
 * (BD-09)-->84
 * @param bdlat
 * @param bdlon
 * @return {{lon: number, lat: number}}
 */
export function bd09ToGps84(bdlat, bdlon) {
  const gcj02 = bd09ToGcj02(bdlat, bdlon);
  return gcjToGps84(gcj02.lat, gcj02.lon);
}
</code></pre>
        </article>
    </section>




</div>

<nav>
    <h2><a href="index.html">Home</a></h2><h3>Modules</h3><ul><li><a href="module-xdh-map.html">xdh-map</a></li><li><a href="module-xdh-map-circle.html">xdh-map-circle</a></li><li><a href="module-xdh-map-dialog.html">xdh-map-dialog</a></li><li><a href="module-xdh-map-draw.html">xdh-map-draw</a></li><li><a href="module-xdh-map-draw-arc.html">xdh-map-draw-arc</a></li><li><a href="module-xdh-map-draw-panel.html">xdh-map-draw-panel</a></li><li><a href="module-xdh-map-drawdown.html">xdh-map-drawdown</a></li><li><a href="module-xdh-map-echarts.html">xdh-map-echarts</a></li><li><a href="module-xdh-map-geo-layer.html">xdh-map-geo-layer</a></li><li><a href="module-xdh-map-group.html">xdh-map-group</a></li><li><a href="module-xdh-map-heat.html">xdh-map-heat</a></li><li><a href="module-xdh-map-html.html">xdh-map-html</a></li><li><a href="module-xdh-map-icon.html">xdh-map-icon</a></li><li><a href="module-xdh-map-image.html">xdh-map-image</a></li><li><a href="module-xdh-map-line.html">xdh-map-line</a></li><li><a href="module-xdh-map-mask.html">xdh-map-mask</a></li><li><a href="module-xdh-map-measure.html">xdh-map-measure</a></li><li><a href="module-xdh-map-overview.html">xdh-map-overview</a></li><li><a href="module-xdh-map-panel.html">xdh-map-panel</a></li><li><a href="module-xdh-map-placement.html">xdh-map-placement</a></li><li><a href="module-xdh-map-pointer.html">xdh-map-pointer</a></li><li><a href="module-xdh-map-polygon.html">xdh-map-polygon</a></li><li><a href="module-xdh-map-popup.html">xdh-map-popup</a></li><li><a href="module-xdh-map-rectangle.html">xdh-map-rectangle</a></li><li><a href="module-xdh-map-scatter.html">xdh-map-scatter</a></li><li><a href="module-xdh-map-text.html">xdh-map-text</a></li><li><a href="module-xdh-map-track.html">xdh-map-track</a></li><li><a href="module-xdh-map-type.html">xdh-map-type</a></li><li><a href="module-xdh-map-warp.html">xdh-map-warp</a></li><li><a href="module-xdh-map-zoom.html">xdh-map-zoom</a></li><li><a href="module-xdh-map-zoom-panel.html">xdh-map-zoom-panel</a></li></ul><h3>Classes</h3><ul><li><a href="ol.interaction.areaSelect.html">areaSelect</a></li><li><a href="ol.interaction.drag.html">drag</a></li><li><a href="ol.source.TileSuperMapRest.html">TileSuperMapRest</a></li></ul><h3>Events</h3><ul><li><a href="module-xdh-map-type.html#~event:change">change</a></li><li><a href="module-xdh-map.html#~event:changeType">changeType</a></li><li><a href="module-xdh-map-pointer.html#~event:copy">copy</a></li><li><a href="module-xdh-map-draw.html#~event:drawend">drawend</a></li><li><a href="module-xdh-map-draw.html#~event:drawstart">drawstart</a></li><li><a href="module-xdh-map-draw.html#~event:modifyend">modifyend</a></li><li><a href="module-xdh-map-draw.html#~event:modifystart">modifystart</a></li><li><a href="module-xdh-map-geo-layer.html#~event:mouseEnter">mouseEnter</a></li><li><a href="module-xdh-map-track.html#~event:move">move</a></li><li><a href="global.html#event:on-boxEnd">on-boxEnd</a></li><li><a href="global.html#event:on-boxStart">on-boxStart</a></li><li><a href="global.html#event:on-dragDown">on-dragDown</a></li><li><a href="global.html#event:on-dragMove">on-dragMove</a></li><li><a href="global.html#event:on-dragUp">on-dragUp</a></li><li><a href="module-xdh-map-draw-panel.html#~event:on-draw">on-draw</a></li><li><a href="module-xdh-map-draw-panel.html#~event:on-draw-end">on-draw-end</a></li><li><a href="module-xdh-map-draw-panel.html#~event:on-edit-start">on-edit-start</a></li><li><a href="module-xdh-map-draw-panel.html#~event:on-finish-draw">on-finish-draw</a></li><li><a href="module-xdh-map-draw-panel.html#~event:on-finish-edit">on-finish-edit</a></li><li><a href="module-xdh-map-draw-panel.html#~event:on-inited">on-inited</a></li><li><a href="module-xdh-map-measure.html#~event:on-measureEnd">on-measureEnd</a></li><li><a href="module-xdh-map-drawdown.html#~event:on-toggle">on-toggle</a></li><li><a href="module-xdh-map.html#~event:ready">ready</a></li><li><a href="module-xdh-map-track.html#~event:start">start</a></li><li><a href="module-xdh-map-track.html#~event:stop">stop</a></li></ul><h3>Global</h3><ul><li><a href="global.html#bd09ToGcj02">bd09ToGcj02</a></li><li><a href="global.html#bd09ToGps84">bd09ToGps84</a></li><li><a href="global.html#bd09ToWgs84">bd09ToWgs84</a></li><li><a href="global.html#capitalize">capitalize</a></li><li><a href="global.html#convertToWgs84">convertToWgs84</a></li><li><a href="global.html#createLayer">createLayer</a></li><li><a href="global.html#createTdtLayer">createTdtLayer</a></li><li><a href="global.html#D2R">D2R</a></li><li><a href="global.html#featureStyleRender">featureStyleRender</a></li><li><a href="global.html#gcj02ToBd09">gcj02ToBd09</a></li><li><a href="global.html#gcj02ToWgs84">gcj02ToWgs84</a></li><li><a href="global.html#gcjToGps84">gcjToGps84</a></li><li><a href="global.html#get">get</a></li><li><a href="global.html#getDistance">getDistance</a></li><li><a href="global.html#getParent">getParent</a></li><li><a href="global.html#gps84ToGcj02">gps84ToGcj02</a></li><li><a href="global.html#keyMap">keyMap</a></li><li><a href="global.html#LAYERS">LAYERS</a></li><li><a href="global.html#mapReady">mapReady</a></li><li><a href="global.html#mix">mix</a></li><li><a href="global.html#mixProps">mixProps</a></li><li><a href="global.html#options">options</a></li><li><a href="global.html#outOfChina">outOfChina</a></li><li><a href="global.html#pi">pi</a></li><li><a href="global.html#prefix">prefix</a></li><li><a href="global.html#props">props</a></li><li><a href="global.html#set">set</a></li><li><a href="global.html#StyleMap">StyleMap</a></li><li><a href="global.html#wgs84ToBd09">wgs84ToBd09</a></li><li><a href="global.html#wgs84ToGcj02">wgs84ToGcj02</a></li></ul>
</nav>

<br class="clear">

<footer>
    Documentation generated by <a href="https://github.com/jsdoc/jsdoc">JSDoc 3.6.2</a> on Sat Mar 21 2020 16:40:44 GMT+0800 (GMT+08:00)
</footer>

<script> prettyPrint(); </script>
<script src="scripts/linenumber.js"> </script>
</body>
</html>
